1. Field
The disclosure relates to a protected anode, a lithium air battery including the protected anode, and a method of manufacturing lithium ion-conductive protective layer.
2. Description of the Related Art
In general a lithium air battery includes an anode capable of intercalating and deintercalating lithium ions, a cathode using oxygen as a cathode active material and a catalyst for oxidizing and reducing oxygen, and a lithium ion-conducting medium disposed between the cathode and the anode.
Lithium air batteries have a theoretical specific energy of about 3000 Wh/kg or greater, which is equivalent to about ten times that of lithium ion batteries. Furthermore, because they are more environmentally friendly and safer in use than lithium ion batteries, lithium air batteries are increasingly being developed.
As an anode active material of a lithium air battery, a lithium metal with high capacity may be used. When lithium metal is used as the anode, solid-phase lithium metal is disassociated to provide lithium ions in an electrolyte during discharging, which are then deposited back as lithium metal during charging. With repeated charging and discharging, dendritic lithium is generated, which consequently lowers charge/discharge efficiency and causes the anode to be disconnected from the cathode. The anode using lithium metal may react with most liquid electrolyte materials to increase the surface resistance of the anode, lower reaction uniformity therein, and deteriorate charge-discharge reversibility. Thus there remains a need for an improved lithium battery anode material.